21340443 has 8 divisors (see below), whose sum is σ = 28611856. Its totient is φ = 14148000.

The previous prime is 21340441. The next prime is 21340469. The reversal of 21340443 is 34404312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21340443 - 2¹ = 21340441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21340441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19108 + ... + 20193.

It is an arithmetic number, because the mean of its divisors is an integer number (3576482).

Almost surely, 2^21340443 is an apocalyptic number.

21340443 is a deficient number, since it is larger than the sum of its proper divisors (7271413).

21340443 is a wasteful number, since it uses less digits than its factorization.

21340443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39485.

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 21340443 is about 4619.5717333969. The cubic root of 21340443 is about 277.3753161154.

Adding to 21340443 its reverse (34404312), we get a palindrome (55744755).

The spelling of 21340443 in words is "twenty-one million, three hundred forty thousand, four hundred forty-three".